Treblog

Saturday, September 6, 2014

After many years of faithful service my Cambridge Audio 540C CD player broke down last week. I got the no disc error. A quick search showed that a broken laser unit was the most likely cause. Luckily the laser unit used in the 540C is a kind of a jelly bean unit: the KSS213C. I ordered one and swapped the old one with the new one and had my player up and running in no time.

Replacing the laser unit is pretty straightforward. Just take it slow and don't force things. See the picture for how to remove the laser unit from the sub-assembly. Reassemble in reverse order.

You must not forget to remove the short-circuit jumper solder blob on the PCB where you connect the flat cable. If you don't remove it, it will not work. Use a hot iron and some desoldering braid to suck up the solder. This should be done in under 2-3 seconds!
There's a small trim-pot on the PCB that affects laser power. Don't change its setting unless you've got the stuff to perform a laser calibration.

Friday, June 20, 2014

I got some money to spend last month so I bought some stuff I wanted for a long time. First there's the Lakland Skyline series Darryl Jones signature bass. After some deliberation I went with the 4 string version in Lake Placid blue. The metallic grey version is nice too but needs a tortoise pickguard IMO. The white version similarly needs a (red) tortoise pickguard. The LPB one comes stock with a white pearloid pickguard, combined with the pearloid block markers it makes for a visually striking bass. Today I applied some oil to the rosewood fretboard. Stock the fretboard is light brown and has a white-ish look. Now with Corcol oil the real luster of the rosewood is visible, it also darkened it a bit. Looks cool.

To satisfy my funky sounds hunger I bought an EBS BassIQ, a triple envelope filter. Funky quack sounds galore. Lastly to keep things in tune I bought the excellent TC Electronic PolyTune 2 tuner. With a ready made DAP flightcase (for a Showmaster 24), some wood, paint and velcro I made my own pedalboard. There's even room to add more effects in the future (UniChorus/Octabass). Too bad the Aguilar DB924 isn't exactly pedalboard friendly in terms of layout.

Fragrance-wise I bought a full bottle of Jo Malone's Lime Basil & Mandarin EDT. I had sampled this one last year and really liked it. Luckily now there's a Jo Malone counter at the Bijenkorf department store in the city center.

Saturday, April 26, 2014

I recently bought a used Samsung SyncMaster 215TW monitor from a friend. It's a big ass wide screen monitor that's so much better than what I had before.

Last week I helped out that same friend in replacing a bad capacitor in the power supply of his Popcorn Hour media player. We swapped the bulging capacitor with a new one and much to his joy it got his media player working again.

Scouring Youtube videos on bad caps I found quite some videos of Samsung monitors and TV's having bad caps in the power supply. Apparently Samsung power supplies in monitors and TV's were infamous for having bad quality caps. Uh-oh... My monitor is still working fine but I still opened it up just to have a peek inside the power supply. Lo and behold I discovered one bulging CapXon cap. I wrote down the values of all the other CapXon caps present, including the still good looking ones, and ordered the lot. Once they're here I'm gonna replace them all with Panasonic FC caps.

Update 1
The caps got here. After about half an hour I had my refurbished monitor up and running again. Bye-bye CapXon crap caps.

Update 2
I discovered that the Panasonic FC caps I used might not be the best choice of caps for this purpose. The Panasonic FC series caps aren't advertised as being low ESR but rather low impedance. The Panasonic FR series caps however are low ESR caps. It's all in the datasheets:

For use in a switched mode power supply (SMPS) as in this and many other monitors, the Panasonic FR series is probably a better choice. Ah well, if it ever comes to changing caps again I'll be using FR's.

For an excellent, albeit low resolution, how-to watch the three part video below.

Some advice on re-capping a PCB. Put a towel on the table to prevent scratches on the screen and/or bezel. Also screws don't roll far on a fluffy towel. Write down the capacitance and the voltage rating on the caps you're gonna replace. Capacitance is a number followed by µF (sometimes erroneously written as uF) e.g. 1000µF. When shopping for caps,
µF
is pronounced as microFarads. The voltage rating is a number followed by V e.g. 25V. When replacing caps ALWAYS replace with the same or higher voltage. NEVER use a cap with a lower voltage rating than the one you're replacing, the cap WILL blow sooner rather than later. If you want to be really safe you could go up a step on the voltage rating but take note: the higher the voltage rating the bigger the cap will be if the capacitance stays the same, usually they are more expensive too. A 1000µF 35V is physically bigger than a 1000µF
25V cap. Bigger caps might not fit the allocated space on the PCB or be to high to fit in the enclosure. If you've got the room to mount them go ahead, it won't hurt. Capacitance should be the same as the one you're replacing.
What brand of caps to buy? I usually buy Panasonic FM and/or FC series, Vishay BC or Elna. Make sure you get low ESR, 105°C caps.
A final note, electrolytic caps, the ones I'm referring to and the ones in the video have a polarity. These have a positive and a negative terminal. Solder the new caps to the PCB in the right orientation. If you accidentally reverse the polarity the cap will likely blow.

If all this is gibberish to you take your monitor to a specialised repair service center!